I'm still not very good at making my Git commit messages (for my blog repo) look good; I'm often just trying to dump all the self-reminders/notes in there kind of messily.
I now know (a bit late):
1. The first line is the most important and should be <50 characters with no period
2. There should be a blank line after the first
3. The rest can be up to 72 char.
I hope one day my commit messages can be clean and consistent!
Good guide here: https://wiki.openstack.org/wiki/GitCommitMessages